Cannot fetch submodule on ARM: "fatal: reference is not a tree"


Fetching submodule produces a error on ARM builds:
Meanwhile, same environment works on x86:

Could anyone please take a look? Maybe there is an old Git version…


fatal: reference is not a tree: means that there’s no such commit.

Indeed, gives a 404.

The submodule must have been force-pushed between the time the jobs were run.
Build log shows that the 3rd job started about the same time as the first two but multi-cpu jobs typically run noticeably slower than amd64 ones.